pH-sensitive polyacrylic acid (PAA) hydrogels trapped with polysodium-p-styrenesulfonate (PSS)

摘要

The preparation of a new type of semi-interpenetration network system of polyacrylic acid (PAA) hydrogel trapped with polysodium-p-styrenesulfonate (PSS) is presented. The structure and response properties of PAA/PSS were investigated by Fourier transform infrared (FTIR) analysis and pH and ionic intensity stimuli-responsive measurement. The FTIR analysis proved the successful intermingling of PSS into PAA. The swelling behavior of PAA hydrogel in an alkaline environment was improved due to the addition of PSS. As the ionic concentration in solution increased, the swelling rate of PAA decreased after adding PSS. However, the swelling velocity of the pure PAA is quicker than that of the PAA/PSS samples since the PSS will enhance the entanglement of this hydrogel network and slow down the swelling velocity. Multi-interactions between the PAA hydrogel network and trapped PSS chains, including electrostatic repulsive interaction, entanglement interaction, ionic intensity interaction, and osmotic pressure, were proposed to explain the earlier-mentioned experimental phenomena.